Just to close the loop on this tiny question completely...

One possible point of confusion here is that United actually does operate an aircraft called a 777-200 which does not have a row 17. It looks like this: http://www.seatguru.com/airlines/Uni...-200_2_New.php

So even if United swears to you that they are positive that the aircraft is a 777-200, it might still be loaded in some way visible to UA agents or to you at united.com with the seat map of the "new configuration 777".

I read your posts to mean that you actually took a look online, and then you posted a link to Seatguru, which has a seat map that looks just like the one you saw online. I'm not sure my read was right and I can imagine how others might have read more ambiguity out of those same posts!

Sorry to pigeonhole on a tiny question of no significance. The possibility of an alternate seat map being available for the flight could confuse a traveler, united.com, or an agent. The "old" and "new" possibilities do look quite different.

Here's UA798, LAX-DEN scheduled for July 26 as a 777-200 with the new international configuration showing on the seat map:



Here's a sample SFO-LHR flight in August, also scheduled as a 777-200 but with the old international configuration showing on the seat map. Most flights to Europe are still scheduled with this old configuration.



(And just for completeness, here's what I did to get a sample picture.)